Move frame_type member from RtpDepacketizer::ParsedPayload to RTPVideoHeader

The latter is also a member of the former. This cleanup is also
a preparation for dropping WebRtcRTPHeader::frameType (or deleting
WebRtcRTPHeader right away), now that it's a video-specific member.


Tbr: kwiberg@webrtc.org # Comment change in modules/include/
Bug: None
Change-Id: I5c1f3f981f0d750713fc9b9b145278150fe32b5d
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/133024
Commit-Queue: Niels Moller <nisse@webrtc.org>
Reviewed-by: Åsa Persson <asapersson@webrtc.org>
Reviewed-by: Danil Chapovalov <danilchap@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#27740}

modules/video_coding/test/stream_generator.cc

@@ -59,7 +59,7 @@ VCMPacket StreamGenerator::GeneratePacket(uint16_t sequence_number,
   VCMPacket packet;
   packet.seqNum = sequence_number;
   packet.timestamp = timestamp;
-  packet.frameType = type;
+  packet.video_header.frame_type = type;
   packet.video_header.is_first_packet_in_frame = first_packet;
   packet.markerBit = marker_bit;
   packet.sizeBytes = size;